1. Field of the Invention
The present invention relates to a tube connector and, more particularly, to an improvement in the structure of a connector for connecting a resin or metal tube having a relatively small diameter less than 15 mm to be arranged as a conduit for feeding oil or air to an automobile or a variety of machines or apparatus.
2. Description of the Prior Art
In the connector of this kind according to the prior art, as shown in FIG. 3, a connector body 21 is formed with a connecting threaded portion 22 on the outer circumference of its leading end, a stepped connecting bore 24 extending therethrough and expanded from and communicating with a small hole 23 formed at the leading end, and an annular groove 25 formed in the inner circumference of the rear portion of the connecting bore 24. Into the connecting bore 24 of the connector body 21, there is inserted a socket member 26 which is formed at its leading end with a cylindrical wall 27 for engaging with a bulging wall T.sub.1 ' of a tube T.sub.1 and at the trailing end of the cylindrical wall 27 with a plurality of free walls which are arranged at a spacing elastically in an expanded manner. When the tube T.sub.1 is connected, the outer circumference of the free walls 28 of the socket member 26 has its land 29 fitted removably in the annular groove 25 of the connector body 21. The trailing end of the free walls 28 is expanded to the outside from the circumferential edge of the trailing end of the connector body 21. Incidentally, reference numeral 30 designates a clearance between the free walls 28 and the outer circumference of the tube T.sub.1.
The connector thus constructed according to the prior art can satisfy its intrinsic object to connect and disconnect the tube T.sub.1 simply and quickly. On the other hand, however, the exposed structure that the trailing end of the free walls 28 is expanded with the land 29 being fitted in the annular groove 25 will probably cause the expanded end to be contacted, vibrated or shocked by another adjacent part, depending upon the state of arrangement, thereby to loosen the connection of the tube T.sub.1 or allow it to come out. In use, moreover, dust or washing water is allowed to invade through the clearance 30 to damage the gas-tightness of the internal O-ring. If the tube is made of a metal, the water will locally rust the outer circumference of the connected portion in the connecting bore 24.